U.S. patent number 10,309,769 [Application Number 15/769,421] was granted by the patent office on 2019-06-04 for light source device and measuring instrument using change over time of intensity of mode-locked oscillated output light.
This patent grant is currently assigned to Pusan National University Industry-University Cooperation Foundation. The grantee listed for this patent is Pusan National University Industry-University Cooperation Foundation. Invention is credited to Myungyung Jeong, Changseok Kim, Gyeonghun Kim, Hwidon Lee.
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United States Patent |
10,309,769 |
Kim , et al. |
June 4, 2019 |
Light source device and measuring instrument using change over time
of intensity of mode-locked oscillated output light
Abstract
The present invention relates to a light source device and a
measuring device which use a change in mode-locked resonated output
light over time using a change in a cycle of an electrical signal
corresponding to a change in the intensity of the output light
according to a mode locking condition for each of different light
paths in a resonator. The light source device includes an
electrical signal generator configured to control the intensity of
an optical signal from the light source device, and an optical gain
unit controlled by periodic electrical signals having cycles
calculated by dividing a round-trip time of photons corresponding
to each of different light paths by an integer multiple. The
intensity of the optical signal is controlled by the optical gain
unit.
Inventors: |
Kim; Changseok (Busan,
KR), Lee; Hwidon (Seoul, KR), Jeong;
Myungyung (Busan, KR), Kim; Gyeonghun (Pohang-si,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Pusan National University Industry-University Cooperation
Foundation |
Busan |
N/A |
KR |
|
|
Assignee: |
Pusan National University
Industry-University Cooperation Foundation (Busan,
KR)
|
Family
ID: |
58557701 |
Appl.
No.: |
15/769,421 |
Filed: |
June 30, 2016 |
PCT
Filed: |
June 30, 2016 |
PCT No.: |
PCT/KR2016/007050 |
371(c)(1),(2),(4) Date: |
April 19, 2018 |
PCT
Pub. No.: |
WO2017/069379 |
PCT
Pub. Date: |
April 27, 2017 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20180306574 A1 |
Oct 25, 2018 |
|
Foreign Application Priority Data
|
|
|
|
|
Oct 23, 2015 [KR] |
|
|
10-2015-0148089 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01B
11/2441 (20130101); G01B 9/02091 (20130101); H01S
3/11 (20130101); H01S 3/08 (20130101); H01S
3/1109 (20130101); H01S 3/094 (20130101); H01S
3/1024 (20130101); H01S 3/083 (20130101); H01S
3/107 (20130101) |
Current International
Class: |
H01S
3/08 (20060101); G01B 11/24 (20060101); H01S
3/094 (20060101); H01S 3/11 (20060101); G01B
9/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2010-112867 |
|
May 2010 |
|
JP |
|
10-0475579 |
|
Mar 2005 |
|
KR |
|
10-2008-0111962 |
|
Dec 2008 |
|
KR |
|
10-1026356 |
|
Apr 2011 |
|
KR |
|
10-2012-0044391 |
|
May 2012 |
|
KR |
|
Primary Examiner: Hansen; Jonathan M
Attorney, Agent or Firm: Rabin & Berdo, P.C.
Claims
What is claimed is:
1. A light source device using a change in intensity of mode-locked
oscillated output light over time, the light source device
comprising: an electrical signal generator configured to control
intensity of an optical signal from the light source device; and an
optical gain unit configured to be controlled by a periodic
electrical signal having a cycle calculated by dividing a
round-trip time of a photon corresponding to each of different
light paths by an integer multiple; and a reflector configured to
generate a reflective signal at a specific light path distance such
that the reflective signal is oscillated at a maximum level when a
specific periodic electrical signal corresponding to a mode locking
condition is applied, wherein the intensity of the optical signal
is controlled by the optical gain unit.
2. The light source device of claim 1, wherein, in a resonator of
the light source device, a reflective optical gain unit, a light
splitter, and a reflector are linearly located.
3. The light source device of claim 1, wherein, in a resonator of
the light source device, a transmissive optical gain unit, a
partial reflector, and a reflector are linearly located.
4. The light source device of claim 1, wherein, in a resonator of
the light source device, a transmissive optical gain unit, a light
circulator, a reflector, and a light splitter are located in a ring
structure.
5. The light source device of claim 1, wherein a resonator of the
light source device comprises a reflector including a scanning
emitter configured to emit and receive light while changing a
position thereof over time, the reflector being in a form in which
a surface and an inner shape of an object are measured on the basis
of a distribution of positions according to a light path distance
difference between one or multiple reflective layers of the
object.
6. The light source device of claim 1, wherein a resonator of the
light source device comprises a reflector including a distribution
emitter configured to emit and receive light by simultaneously
distributing the light to a plurality of paths, the reflector being
in a form in which a surface and an inner shape of an object are
measured on the basis of a distribution of positions according to a
light path distance difference between one or multiple reflective
layers of the object.
7. The light source device of claim 1, wherein a resonator of the
light source device comprises a reflector including an optical
connector configured to emit and receive light via an optical
fiber, the reflector being in a form in which a state of the
optical fiber is sensed and measured on the basis of a distribution
of positions according to a light path distance difference between
one or multiple reflective layers of the optical fiber.
8. The light source device of claim 1, wherein a resonator of the
light source device comprises an electro-optic device configured to
control intensity of an optical signal by receiving a periodic
electrical signal, in place of the optical gain unit.
9. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to control intensity of
an optical signal from a light source device; an optical gain unit
configured to be controlled by a periodic electrical signal having
a cycle time calculated by dividing a round-trip time of a photon
corresponding to each of different light paths by an integer
multiple; and a reflector configured to generate a reflective
signal at a specific light path distance such that the reflective
signal is oscillated at a maximum level when a specific periodic
electrical signal corresponding to a mode locking condition is
applied.
10. The measuring device of claim 9, wherein, in a resonator of the
light source device, a reflective optical gain unit, a light
splitter, and a reflector are linearly located.
11. The measuring device of claim 9, wherein, in a resonator of the
light source device, a transmissive optical gain unit, a partial
reflector, ad a reflector are linearly located.
12. The measuring device of claim 9, wherein, in a resonator of the
light source device, a transmissive optical gain unit, a light
circulator, a reflector, and a light splitter are located in a ring
structure.
13. The measuring device of claim 9, wherein a resonator of the
light source device comprises a reflector including a scanning
emitter configured to emit and receive light while changing a
position thereof over time, the reflector being in a form in which
a surface and an inner shape of an object are measured on the basis
of a distribution of positions according to a light path distance
difference between one or multiple reflective layers of the
object.
14. The measuring device of claim 9, wherein a resonator of the
light source device comprises a reflector including a distribution
emitter configured to emit and receive light by simultaneously
distributing the light to a plurality of paths, the reflector being
in a form in which a surface and an inner shape of an object are
measured on the basis of a distribution of positions according to a
light path distance difference between one or multiple reflective
layers of the object.
15. The measuring device of claim 9, wherein a resonator of the
light source device comprises a reflector including an optical
connector configured to emit and receive light via an optical
fiber, the reflector being in a form in which a state of the
optical fiber is sensed and measured on the basis of a distribution
of positions according to a light path distance difference between
one or multiple reflective layers of the optical fiber.
16. The measuring device of claim 9, wherein a resonator of the
light source device comprises an electro-optic device configured to
control intensity of an optical signal by receiving a periodic
electrical signal, in place of the optical gain unit.
17. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an optical gain unit configured to generate light and amplify
intensity of the light, under periodic control of a periodic
electrical signal; a light splitter configured to split the
intensity of light at a certain ratio; and a reflector configured
to generate a reflective signal at a specific light path distance
such that the reflective signal is oscillated at a maximum level
when a specific periodic electrical signal corresponding to a mode
locking condition is applied.
18. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an optical gain unit configured to generate light and amplify
intensity of the light, under periodic control of a periodic
electrical signal from the electrical signal generator; a reflector
configured to generate a reflective signal at a specific light path
distance such that the reflective signal is oscillated at a maximum
level when a specific periodic electrical signal corresponding to a
mode locking condition is applied; and a partial reflector
configured to transmit a part of the intensity of light and reflect
the remainder.
19. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an optical gain unit configured to generate light and amplify
intensity of the light, under periodic control of a periodic
electrical signal from the electrical signal generator; a light
circulator configured to change a propagation path of the light
output from optical gain unit; a reflector configured to generate a
reflective signal at a specific light path distance such that the
reflective signal is oscillated at a maximum level when a specific
periodic electrical signal corresponding to a mode locking
condition is applied; and a light splitter configured to split the
intensity of light at a certain ratio.
20. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an electro-optic device configured to be controlled by a periodic
electrical signal from the electrical signal generator; an optical
gain unit configured to generate light and amplify intensity of the
light; a light splitter configured to split the intensity of light
at a certain ratio; and a reflector configured to generate a
reflective signal at a specific light path distance such that the
reflective signal is oscillated at a maximum level when a specific
periodic electrical signal corresponding to a mode locking
condition is applied.
21. A measuring device using a change in intensity of mode-locked
oscillated output light over time, the measuring device comprising:
an electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an electro-optic device configured to be controlled by a periodic
electrical signal from the electrical signal generator; an optical
gain unit configured to generate light and amplify intensity of the
light; a reflector configured to generate a reflective signal at a
specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied; and a
partial reflector configured to transmit a part of the intensity of
light and reflect the remainder.
22. A measuring device using a change in intensity of mode-locked
oscillated output light, the measuring device comprising: an
electrical signal generator configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different light
paths by an integer multiple such that the cycles change over time;
an electro-optic device configured to be controlled by a periodic
electrical signal from the electrical signal generator; an optical
gain unit configured to generate light and amplify intensity of the
light; a light circulator configured to change a propagation path
of the light; a reflector configured to generate a reflective
signal at a specific light path distance such that the reflective
signal is oscillated at a maximum level when a specific periodic
electrical signal corresponding to a mode locking condition is
applied; and a light splitter configured to split the intensity of
light at a certain ratio.
Description
TECHNICAL FIELD
The present invention relates to a light source device, and more
particularly, to a light source device and a measuring device which
use a change in a cycle of an electrical signal corresponding to a
change in the intensity of output light according to a mode locking
condition for each of different light paths in a resonator.
BACKGROUND ART
In general, a mode locking technique is a light source technique
for creating a short optical pulse by applying a periodic
electrical signal having a cycle calculated by dividing a
round-trip time of a photon in a resonator by an integer
multiple.
The intensity of an output light pulse oscillated in this case is
maximized when a mode locking condition that a cycle of an
electrical signal should correspond to an integer multiple of a
round-trip time of a photon is satisfied. Generally, such a light
source is applicable to optical communication technology or an
image measuring device configured as a separate device.
An image measuring device using mode-locked laser includes an
optical coherence tomography (OCT) imaging device which obtains a
depth-direction image of a sample using a light coherence
phenomenon.
The OCT imaging device is an imaging system capable of obtaining
and displaying an image of a cross section of an internal tissue of
a sample. The OCT imaging device is a device employing an
interference principle of a light source having a wavelength range
of near-infrared light using an additional optical
interferometer.
In particular, an OCT imaging technique is an imaging technique for
contrasting the inside of a sample in a non-contact manner.
Recently, research has been being actively conducted thereon.
In the OCT imaging device, center wavelength-variable laser is used
to obtain depth-direction information. In the wavelength-variable
laser using mode locking, a cycle of a periodic electrical signal
is changed over time using a dispersion medium or a wavelength
light path difference induction device. Thus, a wavelength of light
is changed using output light oscillating while satisfying a
different mode locking condition for each wavelength. In this case,
the cycle of the periodic electrical signal is linearly changed
over time and thus the intensity of the output light is constantly
maintained while a wavelength thereof is linearly changed.
Various features, such as a high light output, a wide
wavelength-variable range, high wavelength-variable linearity, a
narrow oscillation line width, etc., should be satisfied so that
the wavelength-variable laser may be applicable to imaging
devices.
A maximum image depth or a surface step difference of an optical
tomographic imaging device using the wavelength-variable laser does
not exceed several mm and is determined by a coherence length of a
light source.
Such an OCT imaging device using the wavelength-variable laser
includes a wavelength-variable light source unit, a distance
difference optical interference unit, an optical interference
measuring unit, a time-distance conversion signal processor, etc.
as illustrated in FIG. 1, and employs an additional signal
processing method to obtain distance information by measuring an
interference signal of light which changes over time.
The signal processor performs various signal processing processes
such as correcting linearity according to a temporal change,
time-distance Fourier transformation, etc. and thus has
disadvantages such as time restrictions, an increase in
manufacturing costs, etc.
In particular, a range of depth measurement is limited by a
coherence length of a light source and thus applying the range of
depth measurement to a shape measuring device is limited.
DISCLOSURE
Technical Problem
To address the problems of a sensor measuring device and an image
measuring device and a light source device used therein according
to the related art as described above, the present invention is
directed to providing a light source device and a measuring device
which use a change in a cycle of an electrical signal corresponding
to a change in the intensity of output light according to a mode
locking condition for each of different light paths in a
resonator.
The present invention is directed to providing a light source
device and a measuring device which use a change in the intensity
of mode-locked oscillated output light over time, in which a light
path in a resonator is measured by inputting a cycle of an
electrical signal changing over time to a light source oscillating
output light corresponding to a different electrical signal cycle
input for each light path in a resonator and then measuring a
change in the intensity of output light oscillated to correspond to
the electrical signal cycle over time.
The present invention is directed to providing a light source
device and a measuring device which use a change in the intensity
of mode-locked oscillated output light over time, in which a shape
of a reflector corresponding to a light path is measured by
inputting a frequency of an electrical signal changing over time to
a light source oscillating output light corresponding to a
different electrical signal cycle input for each light path in a
resonator and then measuring a change in the intensity of output
light oscillated to correspond to the frequency of the electrical
signal over time.
The present invention is directed to providing a method of
identifying a light path in a resonator by inducing mode locking
through time control of a radio frequency (RF) corresponding to a
cycle of an electrical signal, and a measuring device employing the
same.
The present invention is directed to providing a light source
device and a measuring device which use a change in the intensity
of mode-locked oscillated output light over time, in which a
reflector of a light source unit is configured as a measuring means
and depth information is obtained by identifying a section in which
mode locking relatively occurs by checking an RF on the basis of a
temporal position of an optical intensity output.
The present invention is directed to providing a light source
device and a measuring device which use a change in the intensity
of mode-locked oscillated output light over time, in which the
intensity of an optical signal is controlled by an optical gain
unit controlled by a periodic electrical signal having a cycle time
calculated by dividing a round-trip time of a photon corresponding
to each of different light paths by an integer multiple.
Objects of the present invention are not, however, limited thereto,
and other objects thereof which are not mentioned herein will be
apparent to those of ordinary skill in the art from the following
description.
Technical Solution
To achieve the above purposes, one aspect of the present invention
provides a light source device which uses a change in intensity of
mode-locked oscillated output light over time, the light source
device including an electrical signal generator configured to
control intensity of an optical signal from the light source
device, and an optical gain unit configured to be controlled by a
periodic electrical signal having a cycle calculated by dividing a
round-trip time of a photon corresponding to each of different
light paths by an integer multiple, wherein the intensity of the
optical signal is controlled by the optical gain unit.
Here, in a resonator of the light source device, a reflective
optical gain unit, a light splitter, and a reflector may be
linearly located.
In a resonator of the light source device, a transmissive optical
gain unit, a partial reflector, and a reflector may be linearly
located.
In a resonator of the light source device, a transmissive optical
gain unit, a light circulator, a reflector, and a light splitter
may be located in a ring structure.
A resonator of the light source device may include a reflector
including a scanning emitter configured to emit and receive light
while changing a position thereof over time, the reflector being in
a form in which a surface and an inner shape of an object are
measured on the basis of a distribution of positions according to a
light path distance difference between one or multiple reflective
layers of the object.
A resonator of the light source device may include a reflector
including a distribution emitter configured to emit and receive
light by simultaneously distributing the light to a plurality of
paths, the reflector being in a form in which a surface and an
inner shape of an object are measured on the basis of a
distribution of positions according to a light path distance
difference between one or multiple reflective layers of the
object.
A resonator of the light source device may include a reflector
including an optical connector configured to emit and receive light
via an optical fiber, the reflector being in a form in which a
state of the optical fiber is sensed and measured on the basis of a
distribution of positions according to a light path distance
difference between one or multiple reflective layers of the optical
fiber.
A resonator of the light source device may include an electro-optic
device configured to control intensity of an optical signal by
receiving a periodic electrical signal, in place of the optical
gain unit.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to control intensity of an optical
signal from a light source device; an optical gain unit configured
to be controlled by a periodic electrical signal having a cycle
time calculated by dividing a round-trip time of a photon
corresponding to each of different light paths by an integer
multiple; and a reflector configured to generate a reflective
signal at a specific light path distance such that the reflective
signal is oscillated at a maximum level when a specific periodic
electrical signal corresponding to a mode locking condition is
applied.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to output periodic electrical signals
having cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an optical gain
unit configured to generate light and amplify intensity of the
light, under periodic control of a periodic electrical signal; a
light splitter configured to split the intensity of light at a
certain ratio; and a reflector configured to generate a reflective
signal at a specific light path distance such that the reflective
signal is oscillated at a maximum level when a specific periodic
electrical signal corresponding to a mode locking condition is
applied.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to output periodic electrical signals
having cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an optical gain
unit configured to generate light and amplify intensity of the
light, under periodic control of a periodic electrical signal from
the electrical signal generator; a reflector configured to generate
a reflective signal at a specific light path distance such that the
reflective signal is oscillated at a maximum level when a specific
periodic electrical signal corresponding to a mode locking
condition is applied; and a partial reflector configured to
transmit a part of the intensity of light and reflect the
remainder.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to output periodic electrical signals
having cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an optical gain
unit configured to generate light and amplify intensity of the
light, under periodic control of a periodic electrical signal from
the electrical signal generator; a light circulator configured to
change a propagation path of the light output from optical gain
unit; a reflector configured to generate a reflective signal at a
specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied; and a
light splitter configured to split the intensity of light at a
certain ratio.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to output periodic electrical signals
having cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an electro-optic
device configured to be controlled by a periodic electrical signal
from the electrical signal generator; an optical gain unit
configured to generate light and amplify intensity of the light; a
light splitter configured to split the intensity of light at a
certain ratio; and a reflector configured to generate a reflective
signal at a specific light path distance such that the reflective
signal is oscillated at a maximum level when a specific periodic
electrical signal corresponding to a mode locking condition is
applied.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light over time, the measuring device including an electrical
signal generator configured to output periodic electrical signals
having cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an electro-optic
device configured to be controlled by a periodic electrical signal
from the electrical signal generator; an optical gain unit
configured to generate light and amplify intensity of the light; a
reflector configured to generate a reflective signal at a specific
light path distance such that the reflective signal is oscillated
at a maximum level when a specific periodic electrical signal
corresponding to a mode locking condition is applied; and a partial
reflector configured to transmit a part of the intensity of light
and reflect the remainder.
Another aspect of the present invention provides a measuring device
which uses a change in intensity of mode-locked oscillated output
light, the measuring device including an electrical signal
generator configured to output periodic electrical signals having
cycles calculated by dividing a round-trip time of photons
corresponding to each of different light paths by an integer
multiple such that the cycles change over time; an electro-optic
device configured to be controlled by a periodic electrical signal
from the electrical signal generator; an optical gain unit
configured to generate light and amplify intensity of the light; a
light circulator configured to change a propagation path of the
light; a reflector configured to generate a reflective signal at a
specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied; and a
light splitter configured to split the intensity of light at a
certain ratio.
Here, the reflector may include a scanning emitter configured to
emit and receive light while changing a position thereof over time,
the reflector being in a form in which a surface and an inner shape
of an object are measured on the basis of a distribution of
positions according to a light path distance difference between one
or multiple reflective layers of the object.
The reflector may include a distribution emitter configured to emit
and receive light by simultaneously distributing the light to a
plurality of paths, the reflector being in a form in which a
surface and an inner shape of an object are measured on the basis
of a distribution of positions according to a light path distance
difference between one or multiple reflective layers of the
object.
The reflector may include an optical connector configured to emit
and receive light via an optical fiber, the reflector being in a
form in which a state of the optical fiber is sensed and measured
on the basis of a distribution of positions according to a light
path distance difference between one or multiple reflective layers
of the optical fiber.
Advantageous Effects
A light source device and a measuring device according to the
present invention which use a change in the intensity of
mode-locked oscillated output light over time as described above
have the following effects.
First, the efficiency of a light source device can be improved
using a change in a cycle of an electrical signal corresponding to
a change in the intensity of output light according to a mode
locking condition for each of different light paths in a
resonator.
Second, a light path in a resonator can be measured by measuring a
change in output light over time by linearly changing a cycle of an
electrical signal in a light source over time, the output light
being oscillated to correspond to the cycle of the electrical
signal.
Third, a shape of a reflector corresponding to a light path can be
measured by measuring a change in output light, which is oscillated
repeatedly, over time by inputting a frequency of an electrical
signal which repeatedly changes.
Fourth, a method of acquiring a light path in a resonator by
inducing mode locking through time control of an RF corresponding
to a cycle of an electrical signal, and an image measuring device
using the method can be provided.
Fifth, a reflector of a light source unit is configured as a
measuring means, and depth information can be obtained by
identifying a section in which mode locking relatively occurs by
checking an RF corresponding to a cycle of an electrical signal
using a temporal position of an optical intensity output.
Accordingly, a measuring device can be easily configured.
Sixth, the intensity of an optical signal can be controlled by an
optical gain unit controlled by a periodic electrical signal having
a cycle time calculated by dividing a round-trip time of a photon
corresponding to each of different light paths by an integer
multiple, thereby increasing optical efficiency.
Seventh, a reflector of a light source unit can be configured as a
measuring means when applied to a measuring device so that an
additional distance difference optical interference unit or a
signal processing operation may be eliminated, thereby increasing
the speed of obtaining an image and decreasing manufacturing
costs.
Eighth, a range of depth measurement can be suppressed from being
limited by a coherence length of a light source and thus can be
easily applicable to an image measuring device.
DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating the configurations of a light
source device and a measuring device according to the related
art.
FIGS. 2 to 7 are diagrams illustrating the configurations of a
light source device and a measuring device which use a change in
the intensity of mode-locked oscillated output light over time,
according to embodiments of the present invention.
FIGS. 8 to 10 are detailed diagrams illustrating the configurations
of reflectors of a light source device and a measuring device which
use a change in the intensity of mode-locked oscillated output
light over time, according to embodiments of the present
invention.
FIG. 11 illustrates an example of a measurement simulation in which
a distribution of intensities of mode-locked oscillated output
light is moved by 1 mm to be proportional to a location of a
reflector by regularly moving the location of the reflector by 1
mm.
BEST MODE
Hereinafter, a light source device and a measuring device which use
a change in the intensity of mode-locked oscillated output light
over time according to exemplary embodiments of the present
invention will be described in detail.
Features and advantages of the light source device and the
measuring device which use a change in the intensity of mode-locked
oscillated output light over time according to embodiments of the
present invention will be apparent from a detailed description of
the following embodiments.
FIGS. 2 to 7 are diagrams illustrating the configurations of a
light source device and a measuring device which use a change in
the intensity of mode-locked oscillated output light over time,
according to embodiments of the present invention.
In the present invention, a reflector of a light source unit is
configured as a measuring means, and depth information may be
obtained by identifying a section in which mode locking relatively
occurs by checking a radio frequency (RF) using a temporal position
of an optical intensity output.
The present invention provides an image measuring device and a
sensor measuring device each having a light source device as
described above.
Each of the light source device and the measuring device which use
a change in the intensity of a mode-locked oscillated output light
over time according to the present invention has a configuration,
in which the intensity of an optical signal is controlled by an
optical gain unit controlled by a periodic electrical signal having
a cycle time calculated by dividing a round-trip time of a photon
corresponding to each of different light paths by an integer
multiple.
To this end, a resonator of a light source device which uses a
change in the intensity of oscillated output light over time has a
form, in which a reflective optical gain unit, a light splitter,
and the reflector are linearly located.
Alternatively, the resonator has a form, in which a transmissive
optical gain unit, a partial reflector, and the reflector are
linearly located.
Alternatively, the resonator has a form, in which a transmissive
optical gain unit, a light circulator, the reflector, and a light
splitter are located in a ring structure.
Here, the reflector may have a form including one or multiple
reflective layers, and the resonator may have a form including an
electro-optic device.
A measuring device having a light source device which uses a change
in the intensity of mode-locked oscillated output light over time
as described above includes an electrical signal generator
configured to output a periodic electrical signal having a cycle
time calculated by dividing a round-trip time of a photon
corresponding to each of different paths by an integer multiple, an
optical gain unit configured to generate light and amplify the
intensity of light and be controlled by a control signal from the
electrical signal generator, and a reflector configured to generate
one or multiple reflective signals in a resonator.
The measuring device using the light source device described above
may be an object surface and inner shape measuring device or a
sensor measuring device which obtains distance information of a
light path of the reflector using a change in the intensity of
mode-locked oscillated output light over time.
However, a light source device and a measuring device which use a
change in the intensity of mode-locked oscillated output light over
time according to the present invention are not limited thereto,
and may be embodied in many different forms, provided that they
include one of the following:
a configuration using a periodic change in a frequency of an
electrical signal corresponding to a change in the intensity of
output light according to a mode locking condition for each of
different light paths in a resonator,
a configuration for measuring a light path in a resonator by
measuring a change in output light, which is oscillated
periodically, over time by inputting a frequency of an electrical
signal changing periodically to a light source oscillating output
light corresponding to a different electrical signal frequency
input for each of light paths in a resonator,
a configuration for measuring a shape of a reflector corresponding
to a light path by measuring a change in output light, which is
oscillated periodically, over time by inputting a frequency of an
electrical signal changing periodically to a light source
oscillating output light corresponding to a different electrical
signal frequency input for each of light paths in a resonator,
a configuration for acquiring a light path in a resonator by
inducing mode locking to occur through time control of an RF of an
electrical signal,
a configuration in which a reflector of a light source unit is
configured as a measuring means and depth information is obtained
by identifying a section in which mode locking relatively occurs by
checking an RF using a temporal position of an optical intensity
output, and
a configuration in which the intensity of an optical signal is
controlled by an optical gain unit controlled by a periodic
electrical signal having a cycle time calculated by dividing a
round-trip time of a photon corresponding to each of different
light paths by an integer multiple.
An image measuring device using a change in the intensity of
mode-locked oscillated output light over time according to the
present invention has a configuration that does not include an
optical interference unit.
The image measuring device further includes a configuration in
which a light path in a resonator is determined by features of a
reflector.
In an image measuring device using a change in the intensity of
mode-locked oscillated output light over time according to the
present invention, an image is measured by measuring the intensity
of an optical signal over time without performing an additional
signal processing process.
The image measuring device includes a configuration for measuring
the intensity of an optical signal through time control of a
frequency of an electrical signal (an RF signal), and a
configuration for obtaining an image through time control of a
frequency of an electrical signal (an RF signal).
A resonator having a reflective measuring unit includes a
configuration for obtaining an image through time control of a
frequency of an electrical signal.
As illustrated in FIG. 2, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 21 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
optical gain unit 22 configured to generate light and amplify the
intensity of light, under periodic control performed using a
periodic electrical signal, a light splitter 23 configured to split
the intensity of light at a certain ratio, and a reflector 24
configured to generate a reflective signal at a specific light path
distance such that the reflective signal is oscillated at a maximum
level when a specific periodic electrical signal corresponding to a
mode locking condition is applied.
As illustrated in FIG. 3, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 31 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
optical gain unit 32 configured to generate light and amplify the
intensity of light, under periodic control performed using a
periodic electrical signal from the electrical signal generator 31,
a reflector 33 configured to generate a reflective signal at a
specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied, and a
partial reflector 34 configured to transmit a part of the intensity
of light and reflect the remainder.
As illustrated in FIG. 4, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 41 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
optical gain unit 42 configured to generate light and amplify the
intensity of light under periodic control performed using a
periodic electrical signal from the electrical signal generator 41,
a light circulator 43 configured to change a propagation path of
light output from the optical gain unit 42, a reflector 44
configured to generate a reflective signal at a specific light path
distance such that the reflective signal is oscillated at a maximum
level when a specific periodic electrical signal corresponding to a
mode locking condition is applied, and a light splitter 45
configured to split the intensity of light at a certain ratio.
As illustrated in FIG. 5, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 51 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
electro-optic device 53 configured to be controlled by a periodic
electrical signal from the electrical signal generator 51, an
optical gain unit 52 configured to generate light and amplify the
intensity of light, a light splitter 55 configured to split the
intensity of light at a certain ratio, and a reflector 54
configured to generate a reflective signal at a specific light path
distance such that the reflective signal is oscillated at a maximum
level when a specific periodic electrical signal corresponding to a
mode locking condition is applied.
As illustrated in FIG. 6, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 61 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
electro-optic device 64 controlled by a periodic electrical signal
from the electrical signal generator 61, an optical gain unit 62
configured to generate light and amplify the intensity of light, a
reflector 63 configured to generate a reflective signal at a
specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied, and a
partial reflector 65 configured to transmit a part of the intensity
of light and reflect the remainder.
As illustrated in FIG. 7, a light source device using a change in
the intensity of mode-locked oscillated output light over time
according to an embodiment of the present invention includes an
electrical signal generator 71 configured to output periodic
electrical signals having cycles calculated by dividing a
round-trip time of photons corresponding to each of different paths
by an integer multiple such that the cycles change over time, an
electro-optic device 72 controlled by a periodic electrical signal
from the electrical signal generator 71, an optical gain unit 73
configured to generate light and amplify the intensity of light, a
light circulator 74 configured to change a propagation path of
light, a reflector 75 configured to generate a reflective signal at
a specific light path distance such that the reflective signal is
oscillated at a maximum level when a specific periodic electrical
signal corresponding to a mode locking condition is applied, and a
light splitter 76 configured to split the intensity of light at a
certain ratio.
A measuring device using a light source device according to an
embodiment of the present invention as described above is an object
surface and inner shape measuring device or a sensor measuring
device which obtains distance information of a light path of a
reflector using a change in the intensity of mode-locked oscillated
output light over time.
The configurations of reflectors of a light source device and a
measuring device according to the present invention will be
described in detail below.
FIGS. 8 to 10 are detailed diagrams illustrating the configurations
of reflectors of a light source device and a measuring device which
use a change in the intensity of mode-locked oscillated output
light over time, according to embodiments of the present
invention.
Configurations of reflectors applicable to a light source device
and a measuring device according to embodiments will be described
below but it will be apparent that embodiments are not limited to
the structures illustrated in FIGS. 8 to 10.
First, as illustrated in FIG. 8, a reflector of each of a light
source device and a measuring device may include a scanning emitter
which has a light collimator, a rotating mirror, and a lens and
which is configured to emit and receive light while changing a
position thereof over time, and may be in a form in which a surface
and an inner shape of an object are measured on the basis of a
distribution of positions according to a light path distance
difference between one or multiple reflective layers of the
object.
Alternatively, as illustrated in FIG. 9, a reflector of each of a
light source device and a measuring device may include a
distribution emitter configured to emit and receive light by
simultaneously distributing light to a plurality of paths, and may
be in a form in which a surface and an inner shape of an object are
measured on the basis of a distribution of positions according to a
light path distance difference between one or multiple reflective
layers of the object.
Alternatively, as illustrated in FIG. 10, a reflector of each of a
light source device and a measuring device may include an optical
connector configured to emit and receive light via an optical
fiber, and may be in a form in which a state of the optical fiber
is sensed and measured on the basis of a distribution of positions
according to a light path distance difference between one or
multiple reflective layers of the optical fiber.
FIG. 11 illustrates an example of a measurement simulation in which
a distribution of intensities of mode-locked oscillated output
light is moved by 1 mm to be proportional to a location of a
reflector by regularly moving the location of the reflector by 1
mm.
In a light source device and a measuring device which use a change
in the intensity of mode-locked oscillated output light over time
according to the present invention as described above, a periodic
change in the frequency of an electrical signal corresponding to a
change in the intensity of output light according to a mode locking
condition for each of different light paths in a resonator is
used.
In particular, the reflector of the light source unit is configured
as a measuring means, and depth information may be obtained by
identifying a section in which mode locking relatively occurs by
checking an RF using a temporal position of an optical intensity
output.
As described above, the present invention may be embodied in many
different forms without departing from essential features of the
present invention.
Accordingly, the embodiments set forth herein should be considered
in descriptive sense only and not for purposes of limitation. The
scope of the invention is defined not by the detailed description
of the invention but by the appended claims, and all differences
within the scope will be construed as being included in the present
invention.
INDUSTRIAL APPLICABILITY
The present invention relates to a light source device and a
measuring device which use a change in a cycle of an electrical
signal corresponding to a change in the intensity of output light
according to a mode locking condition for each of different light
paths in a resonator.
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